Functional and T cell receptor gene usage analysis of cytotoxic T lymphocytes in fresh tumor-infiltrating lymphocytes from human head and neck cancer

The immunoregulatory mechanisms of carcinoma for its survival and development

The immune system in patients detects and eliminates tumor cells, but tumors still progress persistently. The mechanisms by which tumor cells survive under the pressure of immune surveillance are not fully understood. This review is to present the evidence from clinical studies, showing a significant correlation of clinicopathological features of carcinoma with: (1) the loss of classical human leukocyte antigen class I, (2) the up-regulation of non-classical human leukocyte antigen class I, pro-apoptotic Fas ligand and receptor-binding cancer antigen expressed on SiSo cells I, and (3) the formation of immunosuppressive microenvironment by up-regulation of transforming growth factor-beta, Galectin-1, inhibitory ligand B7s, indoleamine 2,3-dioxygenase and arginase, as well as by recruitment of tumor-induced myeloid-derived suppressor cells and regulatory T cells. All of these factors may together protect carcinoma cells from the immune-cytotoxicity.

Head and neck cancer antigens recognized by the humoral immune system

Head and neck cancer in advanced stages are difficult to treat. Therefore, development of new treatment modalities and preventive measures are required. We now report the identification of human head and neck cancer antigens recognized by the humoral immune system. We used the serological analysis of recombinant cDNA expression libraries (SEREX) approach. cDNA libraries from cell lines of squamous cell carcinoma of head and neck (SCCHN) and a normal testicle tissue were screened using sera from six allogeneic SCCHN patients. Total 28 positive clones belonging to 19 different genes were identified, including 12 known genes and 7 unknown ones. Expression analysis on 13 normal tissues and 13 cancer tissues using reverse transcription-PCR (RT-PCR) revealed eight ubiquitously expressed genes, nine of which were expressed preferentially in cancer tissues and two cancer/testis antigens. These antigens we defined may be pertinent candidate antigens for future cancer-diagnosis and related immunotherapy.

Lymphoid cell infiltration into Epstein-Barr virus-positive nasopharyngeal carcinomas

OBJECTIVES

A pilot study was designed to analyze lymphoid cell infiltration in Epstein-Barr virus-positive (EBV+) nasopharyngeal carcinomas (NPCs) and to determine whether this pattern of infiltration is consistent with non-EBV+ head and neck carcinomas or with solid EBV+ tumors in other locations.

STUDY DESIGN

We performed a retrospective analysis of archived NPCs and oral cavity carcinomas.

METHODS

Immunohistochemical staining of the archive material for various markers (CD3, CD8, UCHL-1, S-100, and intercellular adhesion molecule) was performed. Polymerase chain reaction techniques to establish the presence of the EBV genome were used. Cells in different locations were counted under a light microscope by 2 of the authors.

RESULTS

The infiltration pattern of NPCs was different from that of oral cavity carcinomas. Stromal infiltration was significantly denser in oral cavity carcinomas. Tumor nest infiltration was more pronounced in NPCs. The pattern of infiltration was comparable with what has been described for other solid EBV+ tumors.

CONCLUSIONS

The immune response to NPCs is likely to be strongly influenced by the presence of the EBV genome. The pattern of infiltration is similar to that of other non-head and neck EBV+ solid tumors and different from that of EBV- head and neck carcinomas.

CD34+ immune suppressive cells in the peripheral blood of patients with head and neck cancer

Patients with head and neck squamous cell carcinoma (HNSCC) have profound defects in their immune defenses. Using immunofluorescent staining and flow cytometric analysis, we found that most patients with HNSCC have increased levels of CD34+ cells within their peripheral blood. These circulating CD34+ cells contribute to the depressed functional competence of the peripheral blood T-lymphocytes. This was demonstrated by the increased level of proliferative responsiveness to interleukin-2 by the patients' peripheral blood T-cells after depletion of CD34+ cells. These results show the importance of CD34+ cells in contributing to the depression of T-lymphocyte function in patients with HNSCC and suggest that strategies designed to reduce the levels of circulating CD34+ cells may enhance the immune reactivity of the patients' circulating T-lymphocytes against the HNSCC.

A CASP-8 mutation recognized by cytolytic T lymphocytes on a human head and neck carcinoma

Of the antigens recognized on human tumors by autologous cytolytic T lymphocytes, all those defined thus far have been identified on melanoma or renal cell carcinoma. We report here the identification of an antigen recognized by autologous cytolytic T lymphocytes on a human squamous cell carcinoma of the oral cavity. The antigen is encoded by a mutated form of the CASP-8 gene. This gene, also named FLICE or MACH, codes for protease caspase-8, which is required for induction of apoptosis through the Fas receptor and tumor necrosis factor receptor-1. The mutation, which was found in the tumor cells but not in the normal cells of the patient, modifies the stop codon and adds an Alu repeat to the coding region, thereby lengthening the protein by 88 amino acids. The ability of the altered protein to trigger apoptosis appears to be reduced relative to the normal caspase-8. The antigenic peptide is a nonamer presented by HLA-B*3503. The five last amino acids are encoded by the extension of the reading frame caused by the mutation. This, together with previous observations of CDK4 and beta-catenin mutations, suggests that a significant fraction of the point mutations generating a tumor antigen also play a role in the tumoral transformation or progression.

Increased recurrence and metastasis in patients whose primary head and neck squamous cell carcinomas secreted granulocyte-macrophage colony-stimulating factor and contained CD34+ natural suppressor cells

Human head and neck squamous cell carcinomas (HNSCC) that produce high levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) have been shown to contain CD34+ natural suppressor cells that inhibit the activity of intratumoral T-cells. The present study evaluated whether GM-CSF production and the presence of CD34+ cells within primary HNSCC would translate into increased recurrence, metastasis or cancer-related death during the 2 years following surgical excision. Freshly excised primary HNSCC of 20 patients that subsequently developed disease, and of 17 patients that remained with no evidence of disease were analyzed for production of GM-CSF and for CD34+ cell content. The cancers of patients that subsequently developed recurrences or metastatic disease produced almost 4-fold the levels of GM-CSF and had approximately 2.5-fold the number of CD34+ cells as did cancers of patients that remained disease-free. In a second method of analysis, the prognostic significance of high vs. low GM-CSF and CD34+ cell values was evaluated. These analyses showed that patients whose cancers produced high GM-CSF levels or had a high CD34+ cell content had a disproportionately high incidence of recurrence or metastatic disease (94% and 100%, respectively), while the majority of patients whose primary cancers produced low levels of GM-CSF or had a low CD34+ cell content remained disease-free (16% and 19%, respectively). Our results indicate that the presence of CD34+ cells in GM-CSF-producing HNSCC is associated with a poorer prognosis for the cancer patients and suggest the utility of these parameters as prognostic indicators of outcome. Mechanistically, our results suggest that the presence of immune suppressive CD34+ cells in GM-CSF-producing HNSCC leads to increased tumor recurrence or metastasis.